1. Field of the Invention
The present invention relates generally to liquid containers. More particularly, the present invention relates to stable, molded plastic fuel containers adapted to be stacked together when stored or shipped.
2. Description of the Related Art
Molded plastic containers are widely used for storing liquids such as water, fuels, beverages, industrial and agricultural chemicals and the like. Fuel containers of widely varying shapes and sizes are known. Typical containers include some form of hollow receptacle, often cylindrical, that may be integral with a pouring spout or other features. Plastic containers vary in capacity, from common milk bottles that hold one-half or one gallon, to larger fuel tanks with a capacity of five gallons or more.
It is desirable that containers be stable, whether during use or in storage. Obviously containers holding flammable liquids such as gasoline, kerosene, diesel fuel or the like must be designed to be as safe as possible, necessitating designs that promote stability and prevent spillage. For a variety of reasons such as shipping costs, it is also desirable to provide containers that are easily stacked to reduce volume, and which are just as easily unstacked when deployed for use. Concurrently, adequate handles and pouring sports must be convenient, reliable, and safe to use. Handling of heavy, filled or partially filled containers, particularly where combustible fuels are stored must be convenient and non-cumbersome. Various aesthetic visual characteristics are desirable as well.
Stackable bottles or containers are well known in the art. Most designs seek to nest a portion of one container in a receptive region or structure defined in the bottom of a companion container.
For example, U.S. Pat. No. 5,823,345 issued Oct. 20, 1998 shows a modular, stackable receptacle for pool chemicals that includes an upper cover and a lower container portion. The cover includes a continuous rectilinear sidewall having a latch ring, and the upper surface of the cover includes a pour spout which receives a closure cap. The upper surface of the cover also includes a raised crown portion which is coplanar with the closure cap. Both the closure cap and the crown portion have stacking and aligning projections which cooperate with respective recesses formed in the bottom wall of the container portion, which recesses facilitate stable stacking of the receptacles, one atop another.
U.S. Pat. No. 6,230,892 issued May 15, 2001 discloses a stackable, re-usable container with at least one filler and drain opening in the top and with a circumferential upper and lower stacking ring. The upper stacking ring has a slightly larger diameter than the lower stacking ring so that, when stacked one container atop the other, the lower stacking ring of the upper container fits into the recess in the upper stacking ring of the barrel underneath and is snugly centered therein by the vertically protruding circular flange.
U.S. Pat. No. 6,588,612 issued Jul. 8, 2003 discloses a plastic container including side portions having protrusions and/or depressions which nest with one of matching protrusions and depressions of a second container, and with the bottom portion including depressions which nest with the pouring spout and handle of a second container.
U.S. Pat. No. 6,719,161 issued Apr. 13, 2004 discloses a storage container for liquids. A see-through sight visibly exposes the level of product in the container. The container has a wide and stable bottom for stability, and holes in corners to secure a bungee cord. The containers can be stacked for easy storage. The spout is stored in the handle to prevent contamination and to keep a user's hands away from the contents of the container.
U.S. Pat. No. 7,040,509 issued May 9, 2006 discloses a container for storage and dispensing of paint. A unitary, molded plastic container body has an annular neck which is externally threaded and which defines the opening through which contents are dispensed. A dispensing spout is positioned within the neck. The dispensing spout includes two threaded portions, one which engages the neck portion and the other which receives a removable closing cap. The cap is constructed and arranged to close the container opening. A transporting handle is provided and is attached directly to the dispensing spout such that the cap, spout, and handle can be provided as a sub-assembly for threaded engagement onto the container body.
U.S. Pat. Application No. 20060131334 published Jun. 22, 2006 discloses a stackable container for storing and dispensing liquid. A main body comprising a fill port that includes a fill portion and an offset portion wherein the fill portion and offset portion are offset from the main body to provide clearance for filling.
U.S. Pat. Application No. 20070045213 published Mar. 1, 2007 discloses a blow molded, plastic container including a top portion and a bottom portion. Side portions interconnect the top and bottom portions. A pouring spout on one side of the top portion is in the form of a first upward projection, and a second upward projection on the opposed side of the top portion. A handle on the side portion opposed to the pouring spout, and spaced depressions in the bottom portion which nest into the upward projections to form a nested assembly of containers.
U.S. Pat. Application No. 20070114200 published May 24, 2007 discloses a stackable bottle having a storage chamber defined by spaced upper and lower surfaces and planar sidewalls. When stacked, an upper, conical ceiling of a lower bottle mates with a lower convex recess in an upper bottle. Means are provided for interlocking the sides and upper and lower surfaces of the bottles when stacked.
U.S. Pat. Application No. 20110204051 published Aug. 25, 2011 discloses a storage container system including a plurality of containers of various sizes and having interlocking features for minimizing shipping and storage space for the containers. Each container has an open interior, a top surface, a bottom surface, a front surface, a rear surface, and two side surfaces. A closure device is disposed on the top surface of the container for allowing access to the open interior of the container, and the bottom surface defines a bottom indent pocket for interlocking with the closure device of another container. A handle is disposed on the front surface of the container, and the rear surface defines a rear indent pocket for interlocking with the handle of another container.
U.S. Pat. Application No. 20110220530 published Sep. 15, 2011 discloses a stackable container for storing welding electrodes. A container body and a container cap are constructed via thermoplastic injection molding. The container is constructed with walls that define an interior region and complementary upper and lower surfaces.
U.S. Pat. Application No. 20120055833 published Mar. 8, 2012 discloses an ergonomic, stackable watering can for watering plants and flowers. The can comprises a tapered reservoir having a peripheral wall, a bottom and a top opening defining a top edge of the wall, a spout extending from the reservoir, and a handle mounted to the reservoir over a tapered stem which is mounted to the bottom of the reservoir. The peripheral wall further includes an enlargement for receiving a portion of the spout of a similar watering can when the watering cans are assembled in a stack. The handle of a first watering can is inserted in the stem portion of a second watering can when two such watering cans are stacked.
U.S. Pat. Application No. published Oct. 18, 2012 discloses another stackable container. The container comprises a recessed portion and a complimentary top and base which allow for a stack of such containers to be arranged wherein the neck of a lower container is placed within the recessed portion of an upper container, and the base of the upper container contacts the top of the lower container.
U.S. Pat. Application No. 20130213846 published Aug. 22, 2013 discloses a modular, interlocking container suitable for multiple uses. Vertical and horizontal interconnectivity are achieved through interlocking mechanisms. Each modular unit slide-locks with other units to form strong wall and building structures that can be filled with natural earth, sand or other such materials, thereby forming a sturdy structure without the use of mortar, and can adapt to uneven base surfaces typically found in natural terrain.
Other diverse designs of lesser significance to the invention include U.S. Pat. No. 3,658,204 issued Apr. 25, 1972 that discloses a container arrangement for two-component varnishes wherein a large and smaller vessel mechanically interact. The large container comprises a recess corresponding to the shape and size of the smaller, companion container which is coupled to the larger. An open vessel, intended for use as a mixing vessel, is arranged to fit around the large and the small container in the area of the recess.
U.S. Pat. No. 5,669,526 issued Sep. 23, 1997 depicts a spill proof paint can that includes a hollow, cylindrical container, a circular top, and a pouring spout. The lid has a depression with an aperture shape of the container, so that when the lid is placed on the container the lid enters the through the aperture of the container and prevents relative rotation while providing a seal. The pouring spout is disposed in the depression of the lid and is in fluid communication with the aperture of the depression on the lid, so that paint contained in the container can be readily poured.
U.S. Pat. No. 6,352,167 issued Mar. 5, 2002 discloses a combined tool box and fuel tank, that includes a structural combination for consolidated storage. The tool box stands independently in opening and closing operation, which is easy for the operator to take off and put back the tool, and the fuel tank is designed to be separated from the combination for independent use.
When multiple containers are stacked together, the upper surface of one container engages the lower surface or structure of an adjacent container, thereby restraining movements between the containers. However, an inefficient configuration of upper and lower interlocking surfaces may result in unusually large displacements between adjacent containers. Excessive shifting around can result on damages, as frictional wear occurs between abutting surfaces. Bulky or large plastic containers present another difficult problem for stackability and handling because of structural flexure. Repeated deformations of the walls of a fuel container, for example, can eventually result in cracks or product breakage, particularly when the unit is subject to use outdoors, and it is exposed to ultraviolet light and low temperatures.